Replace The Mainboard - Hach DR300 Service Manual

Repairs
Step Description
12 Install the O-ring seal to the optical unit.
Note: Make sure that the contact surfaces on the mainboard are not
touched. Touch the mainboard only at the side.
13 Reassemble the instrument.
Note: Coat the seal groove with Krytox oil.
14 After replacing the optical unit an inspection is necessary.
Refer to Do a service inspection with the test filter set and
service mode on page 28 or to
filter set, service cable, PC and VAP235 software
If the setpoints of the VAA10038.99.V00 Test filter set are not
met, refer to Troubleshooting

5.3 Replace the mainboard

42
Do an inspection with the test
on page 53.
This repair task is also available as a service video on HSO. HSO full access requires
login credentials. First log into HSO and afterwards click on
https://support.hach.com/app/answers/answer_view/a_id/1024331. Select the desired
service video.
Note: Following hyperlink without being logged will end in a permission denied information
screen.
Items to collect:
• Mainboard
• Krytox oil (item no. 16004801)
• VAA10036.99.G00: Service cable
Picture
on page 21.